Apparatus for making uniformly magnetized elements for a gyricon display

Abstract

An apparatus for forming magnetized rotating elements for a rotating element display where all the elements are magnetized in the same orientation is disclosed. The apparatus comprises at least one separator member. Each separator member has a diameter, two opposed surfaces and an edge region in contact with both of the surfaces. Further included is an apparatus for providing at least two liquid flows wherein each one of the liquid flows has an associated separator member and an associated surface on the associated separator member, and each one of the liquid flows is provided across the associated surface of the associated separator members. The liquid flow flows toward the edge region of the associated separator member. The liquid flows are each a flow of hardenable liquid material associated with an optical modulation characteristic, and at least one of the liquid flows containing a magnetic pigment. The separator members are spun and the liquid flows are merged outboard of the edge regions of the one separator members to form a reservoir containing side-by-side amounts of each liquid. When the flow rate of the liquids is high enough, a free jet approximately in a plane outward from the reservoir, the free jet comprising side-by-side amounts of each liquid from the reservoir is formed. A magnetic field, is provided outward from the formation of the free jet and at least a portion of the free jet is passed through the magnetic field to magnetize the magnetic pigment. The magnetic field is aligned transverse to the free jet. If cylindrical elements are desired then the magnetized free jet is hardened into filaments which can be separated into cylindrical elements. If spherical elements are desired then the free jet is broken up into spherical elements before hardening.

What is claimed is:  
     
       1. An apparatus for forming rotating elements for a rotating element display comprising: 
       a) at least one separator member, having a diameter, each separator member having two opposed surfaces and an edge region in contact with both of said surfaces,  
       b) means for providing at least two liquid flows wherein each one of the liquid flows has an associated surface on an associated separator member, wherein each one of the at least two liquid flows is provided across the associated surface of the associated separator member toward the edge region of the associated separator member, the plurality of liquid flows each being a flow of hardenable liquid material associated with an optical modulation characteristic, and at least one of the liquid flows containing a magnetic pigment,  
       c) means for merging the liquid flows outboard of the edge regions of the at least one separator member to form a reservoir containing side-by-side amounts of each liquid,  
       d) means for forming a free jet approximately in a plane outward from the reservoir, the free jet comprising side-by-side amounts of each liquid from the reservoir,  
       e) means for providing a magnetic field, and  
       f) means for passing at least a portion of the free jet through the magnetic field to magnetize the magnetic pigment wherein the magnetic field is aligned transverse to the free jet.  
     
     
       2. The apparatus of claim  1  further comprising: 
       a) means for hardening the free jet to form a filament having at least two segments, each segment being due to a single liquid flow, the at least two segments being joined at a planar interface, each segment being associated with an optical modulation characteristic wherein at least one segment has an associated optical modulation characteristic different from at least one other segment and at least one segment is magnetized.  
     
     
       3. The apparatus of claim  1  wherein the means for forming a free jet comprises means for forming a plurality of free jets and the means for passing the free jet through a magnetic field comprises means for passing the plurality of free jets through the magnetic field wherein the free jets are substantially oriented in the same direction with respect to the magnetic field. 
     
     
       4. The apparatus of claim  1  further comprising: 
       a) means for forming a plurality of substantially spherical portions of the free jet, each portion having at least two segments, each segment being due to a single liquid flow, the at least two segments being joined at a planar interface, each segment being associated with an optical modulation characteristic wherein at least one segment has an associated optical modulation characteristic different from at least one other segment and at least one segment is magnetized, and wherein the magnetized segments of the plurality of substantially spherical portions are magnetized in substantially the same orientation, and  
       b) means for hardening the plurality of substantially spherical portions to form substantially spherical elements, each substantially spherical element being comprised of at least two segments each segment being associated with an optical modulation characteristic wherein at least one segment has an associated optical modulation characteristic different from at least one other segment, at least one segment is magnetized in a given orientation, each substantially spherical element has an anisotropy for providing an electrical dipole moment, the electrical dipole moment rendering the substantially spherical element electrically responsive such that when the substantially spherical element is rotatably disposed in an electric field while the electrical dipole moment of the substantially spherical element is provided, the substantially spherical element tends to rotate to an orientation in which the electrical dipole moment aligns with the field, and wherein the magnetized segments of the plurality of substantially spherical elements are magnetized in substantially the same orientation.  
     
     
       5. The apparatus of claim  1  further comprising: 
       a) means for forming a plurality of substantially spherical portions of the free jet, each portion having at least two segments, each segment being due to a single planar stream, the at least two segments being joined at a planar interface, each segment being associated with an optical modulation characteristic wherein at least one segment has an associated optical modulation characteristic different from at least one other segment and at least one segment contains magnetic pigment such that the plurality of substantially spherical portions pass through the magnetic field in substantially the same orientation with respect to the magnetic field, and  
       b) means for hardening the plurality of magnetized substantially spherical portions to form substantially spherical elements, each substantially spherical element being comprised of at least two segments each segment being associated with an optical modulation characteristic wherein at least one segment has an associated optical modulation characteristic different from at least one other segment, at least one segment is magnetized in a given orientation, each hardened substantially spherical element has an anisotropy for providing an electrical dipole moment, the electrical dipole moment rendering the substantially spherical element electrically responsive such that when the substantially spherical element is rotatably disposed in an electric field while the electrical dipole moment of the substantially spherical element is provided, the substantially spherical element tends to rotate to an orientation in which the electrical dipole moment aligns with the field, and wherein the magnetized segments of the plurality of substantially spherical hardened elements are magnetized in substantially the same orientation.  
     
     
       6. The apparatus of claim  1  further comprising: 
       a) means for forming a plurality of substantially spherical portions of the free jet, each portion having at least two segments, each segment being due to a single planar stream, the at least two segments being joined at a planar interface, each segment being associated with an optical modulation characteristic wherein at least one segment has an associated optical modulation characteristic different from at least one other segment and at least one segment contains magnetic pigment,  
       b) means for hardening the plurality of substantially spherical portions just formed, each hardened substantially spherical portion being comprised of at least two segments each segment being associated with an optical modulation characteristic wherein at least one segment has an associated optical modulation characteristic different from at least one other segment, at least one segment is magnetized in a given orientation, each hardened substantially spherical portion has an anisotropy for providing an electrical dipole moment, the electrical dipole moment rendering the hardened substantially spherical element electrically responsive such that when the hardened substantially spherical element is rotatably disposed in an electric field while the electrical dipole moment of the substantially spherical element is provided, the substantially spherical element tends to rotate to an orientation in which the electrical dipole moment aligns with the field, and  
       c) means for passing hardened substantially spherical portions through a magnetic field in substantially the same orientation with respect to the magnetic field to form magnetized substantially spherical elements wherein the magnetized segments of the plurality of substantially spherical elements are magnetized in substantially the same orientation.  
     
     
       7. The apparatus of claim  1  wherein there are at least two separator members. 
     
     
       8. The apparatus of claim  7  wherein the means for providing at least two liquid flows comprises means for providing three liquid flows. 
     
     
       9. The apparatus of claim  7  wherein the means for providing at least two liquid flows comprises means for providing four liquid flows. 
     
     
       10. The apparatus of claim  1  wherein the means for providing a magnetic field comprises means for providing a steady magnetic field. 
     
     
       11. The apparatus of claim  10  wherein the means for providing a steady magnetic field comprises a pair of magnets. 
     
     
       12. The apparatus of claim  11  wherein the pair of magnets comprises a pair of toroidal shaped magnets having a diameter larger than the diameter of the at least one separator member and spaced from each other across the plane of the free jet. 
     
     
       13. The apparatus of claim  1  wherein the means for providing an magnetic field comprises an electromagnet.